In recent years, easily portable and battery-driven apparatuses are in wide use. Some portable apparatuses that are installed with an operating system (OS) are automatically suspended for power saving, when there is no task to do, and are automatically resumed when some task arises thereafter. The “suspend” and “resume” are functions designed to save power without lowering the uses' work efficiency. In the “suspend” processing, the portable apparatuses are suspended, with the states being maintained, and in the “resume” processing, the suspended portable apparatuses are returned to the original states in which they were immediately before the “suspend” processing.
The “suspend” processing and “resume” processing are controlled by the OS, which manages resources of a portable apparatus, and various proposals have been made to enhance the efficiency of the “suspend” processing and “resume” processing.
The power consumption of a portable apparatus can be reduced when the apparatus is in the suspend mode. It should be noted, however, that the suspend processing and the resume processing consume the power (of the battery of the portable apparatus). Therefore, frequent use of the suspend processing and resume processing should be avoided.
Up until now, little attention has been paid to the fact that the suspend processing and the resume processing do require power, and few effective methods for avoiding frequent use of the suspend processing and the resume processing have been considered.